Aug 292014
 
Aug 292014
 

“You may say I’m a dreamer, but I’m not the only one,” sang John Lennon in his 1971 song ImagineAnd thanks to the dreams of a BYU student, we now know more about where and how imagination happens in our brains.

Stefania Ashby and her faculty mentor devised experiments using MRI technology that would help them distinguish pure imagination from related processes like remembering.

“I was thinking a lot about planning for my own future and imagining myself in the future, and I started wondering how memory and imagination work together,” Ashby said. “I wondered if they were separate or if imagination is just taking past memories and combining them in different ways to form something I’ve never experienced before.”

There’s a bit of scientific debate over whether memory and imagination truly are distinct processes. So Ashby and her faculty mentor devised MRI experiments to put it to the test.

They asked study participants to provide 60 personal photographs for the “remember” section of the experiment. Participants also filled out a questionnaire beforehand to determine which scenarios would be unfamiliar to them and thus a better fit for the “imagine” section.

The researchers then showed people their own photographs during an MRI session to elicit brain activity that is strictly memory-based. A statistical analysis revealed distinctive patterns for memory and imagination.

“We were able to see the distinctions even in those small regions of the hippocampus,” Ashby said. “It’s really neat that we can see the difference between those two tasks in that small of a brain region.”

Ashby co-authored the study with BYU psychology and neuroscience professor Brock Kirwan for the journal Cognitive Neuroscience. Kirwan studies memory at Brigham Young University, and Ashby is one of many students that he has mentored.

“Stefania came in really excited about this project, she pitched it to me, and basically sold it to me right there,” Kirwan said. “It was really cool because it gave me a chance to become more immersed and really broaden my horizons.”

Stefania graduated in 2011 and is currently working as a research associate at UC Davis, where she uses neuroimaging to study individuals at risk of psychotic disorders such as schizophrenia. Her plan is to earn a Ph.D. in neuroscience and continue researching.

Each year several hundred BYU graduates like Stefania fan out across the country to Ph.D. programs at other universities. Mentoring is a large reason why BYU ranks so highly as a Ph.D. launch pad. According to the National Science Foundation, BYU ranks 5th in the nation for the number of graduates who go on to earn doctorate degrees.

Source: Brigham Young University

Aug 292014
 

Brain Research ChallengesBy manipulating neural circuits in the brain of mice, scientists have altered the emotional associations of specific memories. The research, led by Howard Hughes Medical Institute investigator Susumu Tonegawa at the Massachusetts Institute of Technology (MIT), reveals that the connections between the part of the brain that stores contextual information about an experience and the part of the brain that stores the emotional memory of that experience are malleable.

Altering those connections can transform a negative memory into a positive one, Tonegawa and his MIT colleagues report in the August 28, 2014, issue of the journal Nature.

“There is some evidence from pyschotherapy that positive memory can suppress memories of negative experience,” Tonegawa says, referring to treatments that reduce clinical depression by helping patients recall positive memories. “We have shown how the emotional valence of memories can be switched on the cellular level.”

The episodes and events that we experience become intimately associated with emotion as they are stored as memories in the brain. Recalling a favorite vacation may summon pleasure for years to come, whereas the fear that accompanies a memory of assault might cause a victim to never return to the scene of the crime. Tonegawa explains that the contextual information about these events – where and when they happened – is recorded in the brain’s hippocampus, whereas the emotional component of the memory is stored separately, in a brain region called the amygdala. “The amygdala can store information with either a positive or negative valence, and associate it with a memory,” Tonegawa explains.

Last year, Tonegawa and his colleagues reported that by artificially activating the small set of cells that stored a specific memory in a mouse, they could create a new, false memory. In that study, the team made the cells that stored a memory of a safe environment sensitive to light, so that they could be manipulated by the researchers. Switching on those cells while subjecting the animal to a mild shock in a new environment caused the mouse to fear the original environment, even though it had had no unpleasant experiences there.

In those experiments, the scientists had caused the mice to associate a neutral setting with fear. Now Tonegawa and his colleagues wanted to see if he could alter a memory that was already associated with emotion. Once an animal had developed fear of a place, could the memory of that place be made pleasurable instead?

To find out, the scientists began by placing male mice in a chamber that delivered a mild shock. As the mouse formed of memory of this dangerous place, Tonegawa’s team used a method it had previously developed to introduce a light-sensitive protein into the cells that stored the information. By linking the production of the light-sensitive protein to the activation of a gene that is switched on as memories are encoded, they targeted light-sensitivity to the cells that stored the newly formed memory.

The mice were removed from the chamber and a few days later, the scientists artificially reactivated the memory by shining a light into the cells holding the memory of the original place. The animals responded by stopping their explorations and freezing in place, indicating they were afraid.

Now the scientists wanted to see if they could overwrite the fear and give the mice positive associations to the chamber, despite their negative experience there. So they placed the mice in a new environment, where instead of a shock they had the opportunity to interact with female mice. As they did so, the researchers activated their fear memory-storing neurons with light. The scientists activated only one subset of memory-storing neurons at a time – either those in the context-storing hippocampus or those in the emotion-storing amygdala. They then tested the emotional association of the memory of the original chamber by giving mice the opportunity to move away from an environment in which the memory was artificially triggered.

Reactivating the amygdala component of the memory while the male mice had the pleasurable experience of interacting with females failed to change the fear response driven by those amygdala neurons. Consequently, mice retained their fear. When the researchers reactivated the memory-storing cells in the hippocampus while the mice interacted with females, however, the memory cells in the hippocampus acquired a new emotional association. Now the mice sought out environments that triggered the memory.

“So the animal acquired a pleasure memory,” Tonegawa says. “But what happened to the original fear memory? Is it still there or is it gone?” When they put the animals back in the original chamber, where they had experienced the unpleasant shock, the animals showed less fear and more exploratory and reward-seeking behaviors. “The original fear memory is significantly changed,” Tonegawa concludes.

The researchers had similar results in experiments where they switched the emotion of a memory in the opposite direction – allowing mice to first develop a pleasurable memory of the chamber, then artificially activating the memory-storing cells in the hippocampus while the animals experienced a shock. In those mice, the pleasurable response linked to the hippocampal memory cells was replaced with a fear response.

The experiments indicate that the cells that store the contextual components of a memory form impermanent or malleable connections to the emotional components of that memory. Tonegawa explains that while a single set of neurons in the hippocampus stores the contextual information about a memory, there are two distinct sets of neurons in the amygdala to which they can connect: one set responsible for positive memory, the other responsible for negative memory. Circuits connect the hippocampal cells to each of the two populations of cells in the amygdala. “There is a competition between these circuits that dictates the overall emotional value and [positive or negative] direction of a memory,” Tonegawa says.

In an accompanying News & Views article in Nature, Tomonori Takeuchi and Richard G.M. Morris of the University of Edinburgh, state, “What is so intriguing about this study is that the memory representations associated with a place are dissected into their network components and, rather than re-exposing the animals to the training situation to achieve a change, light is used to selectively reactivate the representation of the ‘where’ component of a memory and then change its ‘what’ association.”

Tonegawa emphasizes that their success in switching the emotion of a memory in mice does not translate to an immediate therapy for patients. There is no existing technology to manipulate neurons in people as they did in their mouse experiments. However, he says, the findings suggest that neural circuits connecting the hippocampus and the amygdala might be targeted for the development of new drugs to treat mental illness.

Source: Howard Hughes Medical Institute

Aug 292014
 

Chinese medicineA herbal preparation prescribed by a Chinese herbal medication practitioner in Melbourne for back pain resulted in life-threatening heart changes, prompting a team of intensive care and emergency physicians to call for appropriate patient education by practitioners who prescribe complementary medications.

Writing in Emergency Medicine Australasia, the journal of the Australasian College for Emergency Medicine, emergency medicine trainees Dr Angelly Martinez and Dr Nicky Dobos from the Intensive Care Unit at the Royal Melbourne Hospital and emergency medicine trainee Dr Joe-Anthony Rotella and emergency physician Dr Shaun Greene from Austin Health, described the case of a woman who began experiencing facial tingling and numbness within minutes of ingesting a preparation containing aconite.

These symptoms were followed by nausea, vomiting, diarrhoea and abdominal pain 30 minutes later.

Aconite is a class of plant that is also known as wolfsbane or devil’s helmet.

The patient was given verbal instructions by the Chinese herbal medicine practitioner to boil the mixture of plant and animal material for 45 minutes prior to ingestion, although she boiled it for only 30 minutes.

By the time she was admitted to the emergency department, she had developed severe cardiovascular toxicity, which required admission to the intensive care unit.

“Aconite poisoning is not a toxicological condition that many Australian doctors would be aware of and has not been described in Australian peer reviewed medical literature for over 20 years,” said Dr Shaun Greene.

“The case serves as a reminder that clinicians can access expert poisoning advice from a clinical toxicologist via the Poisons Information Centre system accessible via telephone (13 11 26) throughout Australia.”

The Chinese herbal practitioner reported prescribing  “Chuan Wu”, “Cao Wu” and “Fu Zi” to improve general circulation and reduce musculoskeletal pain.

There is no commercially available biological assay for aconite in Australia.

“Chuan Wu”, “Fu Zi” (both derived from Aconitum carmichaeli) and “Cao Wu” (Aconitum kusnezoffii), are the most common forms of aconite used medicinally.

This case illustrates the potentially lethal nature of aconite poisoning.

Chinese herbal medicines are being used increasingly in Australia, as the Chinese immigrant population increases.

“Regulatory agencies should enact measures to ensure patients are provided with accurate advice regarding safe use of Chinese herbal medicines,” Dr Greene said.

Source: Wiley

Aug 292014
 

Women handshaking outdoorsParents have long told their children to mind their Ps and Qs, and remember to say thank you. Now the evidence is in on why it matters.

A UNSW Australia-led study has shown for the first time that thanking a new acquaintance for their help makes them more likely to seek an ongoing social relationship with you.

“Saying thank you provides a valuable signal that you are someone with whom a high quality relationship could be formed,” says UNSW psychologist Dr Lisa Williams, who conducted the research with Dr Monica Bartlett of Gonzaga University in the US.

The study, to be published in the journal Emotion, involved 70 university students who provided advice to a younger student. Some of those advice-givers were thanked for their advice.

The study was designed to test a theory proposed two years ago to explain the benefits to individuals and society of the emotion of gratitude. This find-remind-and-bind theory suggests gratitude helps people develop new relationships (find), build on existing relationships (remind), and maintain both (bind).

The study tested the first aspect of the theory – finding.

The university students were led to believe they were mentoring a high school student, and were asked to comment on a university admissions essay, supposedly written by the mentee.

In reply, all mentor participants received a hand written note from their supposed mentee. In about half the cases the note included an expression of gratitude: “Thank you SO much for all the time and effort you put into doing that for me!”

The university students who were thanked were more likely to provide their contact details, such as their phone number or email address, for the mentee than those who were not thanked.

The grateful mentees were also rated as having significantly warmer personalities. The results suggest that the reason why people ‘find’ grateful others is because of this perceived warmth.

Perhaps surprisingly, this kind of experiment had not been conducted before.

“Our findings represent the first known evidence that expression of gratitude facilitates the initiation of new relationships among previously unacquainted people,” says Dr Williams.

“With more people communicating by social media, such as Facebook and Twitter, it would be interesting to find out whether just observing someone express gratitude increases another person’s desire to form a relationship with them.”

Source: University of New South Wales 

Aug 292014
 

78481_webThe steep decline in the use of hormone therapy has spawned a prevalent but preventable side effect: millions of women suffering in silence with hot flashes, according to a study by a Yale School of Medicine researcher and colleagues.

In the study published in the Aug. 27 online issue of the journal Menopause, the team found that moderate to severe hot flashes — also called vasomotor symptoms (VMS) — are not treated in most women. Women with VMS experience more than feeling hot; other frequently occurring symptoms include fatigue, sleep disturbance, depression, anxiety, and impaired short-term memory.

“Not treating these common symptoms causes many women to drop out of the labor force at a time when their careers are on the upswing,” said Philip Sarrel, M.D., emeritus professor in the Departments of Obstetrics, Gynecology & Reproductive Sciences, and Psychiatry. “This also places demands on health care and drives up insurance costs.”

Sarrel and colleagues used data on health insurance claims to compare over 500,000 women, half with and half without hot flashes. The team calculated the costs of health care and work loss over a 12-month period. Participants were all insured by Fortune 500 companies.

The team found that women who experienced hot flashes had 1.5 million more health care visits than women without hot flashes. Costs for the additional health care was $339,559,458. The cost of work lost was another $27,668,410 during the 12-month study period.

Hot flashes are the result of loss of ovarian hormones in the years just before and after natural menopause. For women who have a hysterectomy, symptoms may occur almost immediately following surgery and are usually more severe and long lasting. More than 70% of all menopausal women and more than 90% of those with hysterectomies experience VMS that affect daily function.

In the past, hot flashes were readily treated with either hormone therapy or alternative approaches. However, following the 2002 publication of the findings in the Women’s Health Initiative Study, there has been a sharp drop in the use of hormone therapy due to unfounded fears of cancer risks, according to Sarrel.

“Women are not mentioning it to their healthcare providers, and providers aren’t bringing it up,” said Sarrel. “The symptoms can be easily treated in a variety of ways, such as with low-dose hormone patches, non-hormonal medications, and simple environmental adjustments such as cooling the workplace.”

Source: Yale University

Aug 292014
 

ConfidentOver confident people can fool others into believing they are more talented than they actually are, a study has found.

These ‘self-deceived’ individuals could be more likely to get promotions and reach influential positions in banks and other organisations. And these people are more likely to overestimate other people’s abilities and take greater risks, possibly creating problems for their organisations.

The study by researchers from Newcastle University and the University of Exeter, has also found that those who are under confident in their own abilities are viewed as less able by their colleagues.

The findings, which will be published in the journal PLOS ONE today, are the first time a link has been found between a person’s view of their own ability and how others see their abilities, and could partially explain financial collapses and other disasters.

As part of the research the team asked 72 students to rate their own ability and the ability of their peers after the first day of their course. Of those, 32 students (about 45%) were under confident in their ability as compared to their final mark, 29 students (40%) were overconfident and 11 students (15%) were accurate in their assessments of their own ability.

There was a positive correlation between the grades students predicted for themselves and the grades others predicted for them. In other words, students who predicted higher grades for themselves were predicted to have higher grades by others, irrespective of their actual final score. The same applied to those who were under confident.

The task was repeated after six weeks of the course when the students knew each other better and the findings remained the same. Those who were over confident were over rated by others.

Study author Dr Vivek Nityananda, research associate at Newcastle University explains: “These findings suggest that people don’t always reward the most accomplished individual but rather the most self-deceived.

“We think this supports an evolutionary theory of self-deception. It can be beneficial to have others believe you are better than you are and the best way to do this is to deceive yourself – which might be what we have evolved to do.

“This can cause problems as over confident people may also be more likely to take risks. So if too many people overrate themselves and deceive others about their abilities within organisations then this could lead to disastrous consequences such as airplane crashes or financial collapses.”

Joint lead author, Dr Shakti Lamba, of The University of Exeter added: “If over confident people are more likely to be risk prone then by promoting them we may be creating institutions, such as banks and armies, that are more vulnerable to risk.”

Source: University of Exeter

Aug 282014
 

pianoAccording to researchers at the University of Montreal, the regions of the brain below the cortex play an important role as we train our bodies’ movements and, critically, they interact more effectively after a night of sleep.  While researchers knew that sleep helped us the learn sequences of movements (motor learning), it was not known why.

“The subcortical regions are important in information consolidation, especially information linked to a motor memory trace. When consolidation level is measured after a period of sleep, the brain network of these areas functions with greater synchrony, that is, we observe that communication between the various regions of this network is better optimized. The opposite is true when there has been no period of sleep,” said Karen Debas, neuropsychologist at the University of Montreal and leader author of the study. A network refers to multiple brain areas that are activated simultaneously.

To achieve these results, the researchers, led by Dr. Julien Doyon, Scientific Director of the Functional Neuroimaging Unit of the Institut universitaire de gériatrie de Montréal Research Centre, taught a group of subjects a new sequence of piano-type finger movements on a box. The brains of the subjects were observed using functional magnetic resonance imaging during their performance of the task before and after a period of sleep. Meanwhile, the same test was performed by a control group at the beginning and end of the day, without a period of sleep.

The researchers had already shown that the putamen, a central part of the brain, was more active in subjects who had slept. Furthermore, they had observed improved performance of the task after a night of sleep and not the simple passage of daytime. Using a brain connectivity analysis technique, which identifies brain networks and measures their integration levels, they found that one network emerged from the others—the cortico-striatal network—composed of cortical and subcortical areas, including the putaman and associated cortical regions. “After a night of sleep, we found that this network was more integrated than the others, that is, interaction among these regions was greater when consolidation had occurred. A night of sleep seems to provide active protection of this network, which the passage of daytime does not provide. Moreover, only a night of sleep results in better performance of the task,” Debas said.

These results provide insight into the role of sleep in learning motor skills requiring new movement sequences and reveal, for the first time, greater interaction within the cortico-striatal system after a consolidation phase following sleep. “Our findings open the door to other research opportunities, which could lead us to better understand the mechanisms that take place during sleep and ensure better interaction between key regions of the brain. Indeed, several other studies in my laboratory are examining the role of sleep spindles—brief physiological events during non-rapid eye movement sleep—in the process of motor memory trace consolidation,” Doyon said. “Ultimately, we believe that we will better be able to explain and act on memory difficulties presented by certain clinical populations who have sleeping problems and help patients who are relearning motor sequences in rehabilitation centres,” Debas said.

Source: University of Montreal

Aug 282014
 

MovieDo you feel sadder watching a documentary about war or a drama about a young person dying of cancer? According to a new study in the Journal of Consumer Research, consumers mistakenly believe they will have stronger emotional reactions when stories are based on true events rather than fiction.

“Consumers may choose to read a tragic fictional story because they assume that knowing it was fictional would make them less sad than reading a less dramatic, but true story,” write authors Jane E. J. Ebert (Brandeis University) and Tom Meyvis (New York University). “However, the fictional nature does not alter the impact of the tragic story, leaving them more emotionally distraught than if they had read the true story instead.”

In the midst of emotional experiences, consumers are so absorbed by the actual experience that they might be unable to take into account the fictional nature of the story. The authors tested this in one study by informing viewers that a film they were about to see was fictional. These viewers did feel less sad after watching this fictional movie, but only when breaks were provided, allowing the viewers to mull over the fact that the story was not true.

In another study, participants read a tragic story and were asked how they would have felt if they had known that the event in the story really happened or was completely fictional. Not surprisingly, participants indicated they would have felt substantially sadder had they known the story was real. Another group of participants was asked to read the same story and told that the event was either real or fictional. These participants felt sad after reading the story regardless of whether the event actually happened.

Publishers and movie studios should note that underestimating the emotional impact of fictional stories may lead consumers to choose less enjoyable books and movies just because they are based on a true story. “Emphasizing realism may indeed make consumers more likely to choose these options, as consumers tend to believe that true stories will have a greater emotional impact than fictional stories. However, our results suggest that while emphasizing realism may increase sales, it does not necessarily increase satisfaction,” the authors conclude.

Source: University of Chicago Press Journals

Aug 282014
 

man with tomatoMen who eat over 10 portions a week of tomatoes have an 18 per cent lower risk of developing prostate cancer, new research suggests.

With 35,000 new cases every year in the UK, and around 10,000 deaths, prostate cancer is the second most common cancer in men worldwide.

Rates are higher in developed countries, which some experts believe is linked to a Westernised diet and lifestyle.

To assess if following dietary and lifestyle recommendations reduces risk of prostate cancer, researchers at the Universities of Bristol, Cambridge and Oxford looked at the diets and lifestyle of 1,806 men aged between 50 and 69 with prostate cancer and compared with 12,005 cancer-free men.

The NIHR-funded study, published in the medical journal Cancer Epidemiology, Biomarkers and Prevention, is the first study of its kind to develop a prostate cancer ‘dietary index’ which consists of dietary components – selenium, calcium and foods rich in lycopene – that have been linked to prostate cancer.

Men who had optimal intake of these three dietary components had a lower risk of prostate cancer.

Tomatoes and its products – such as tomato juice and baked beans – were shown to be most beneficial, with an 18 per cent reduction in risk found in men eating over 10 portions a week.

This is thought to be due to lycopene, an antioxidant which fights off toxins that can cause DNA and cell damage. Vanessa Er, from the School of Social and Community Medicine at the University of Bristol and Bristol Nutrition BRU, led the research.

She said: “Our findings suggest that tomatoes may be important in prostate cancer prevention. However, further studies need to be conducted to confirm our findings, especially through human trials. Men should still eat a wide variety of fruits and vegetables, maintain a healthy weight and stay active.”

The researchers also looked at the recommendations on physical activity, diet and body weight for cancer prevention published by the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR).

Only the recommendation on plant foods – high intake of fruits, vegetables and dietary fibre – was found to be associated with a reduced risk of prostate cancer. As these recommendations are not targeted at prostate cancer prevention, researchers concluded that adhering to these recommendations is not sufficient and that additional dietary recommendations should be developed.

Source: University of Bristol

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